Films from oat spelt arabinoxylan plasticized with glycerol and sorbitol

The development of packaging films based on renewable materials is an important and active area of research today. This is the first extensive study focusing on film‐forming properties of an agrobiomass byproduct, namely, oat spelt arabinoxylan. A plasticizer was needed for cohesive film formation, and glycerol and sorbitol were compared. The tensile properties of the films varied with the type and amount of the polyol. With a 10% (w/w) plasticizer content, the films containing glycerol had higher tensile strength than the films containing sorbitol, but with a 40% plasticizer content, the result was the opposite. Sorbitol‐plasticized films retained their tensile properties better than films with glycerol during 5 months of storage. The films were semicrystalline with similar crystallinity indices of 0.20–0.26. The largest crystallites (9.5 nm) were observed in the film with 40% glycerol. The softening of films with 40% (w/w) glycerol started at a significantly lower relative humidity (RH) than that of the corresponding sorbitol‐containing films. The films with sorbitol also had lower water vapor permeability (WVP) than the films with glycerol. The films plasticized with 10% (w/w) sorbitol had a WVP value of 1.1 g mm/(m²·d·kPa) at the RH gradient of 0/54%. The oxygen permeability of films containing 10% (w/w) glycerol or sorbitol was similar: 3 cm³·μm/(m²·d·kPa) at 50–75% RH. A higher plasticizer content resulted in more permeable films. Permeation of sunflower oil through the films was not detected. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The trend of reduced hop‐content in Pilsner‐type beer in Germany. A change in taste?

A time series analysis of the development of bitterness units (BU) of a collective of 1,202 Pilsner beer samples analysed between 1983 and 2013 shows a small but statistically significant decline from values of around 30 BU in the 1980s to values of around 27 in the last years. The results confirm a trend to lower hopped Pilsner beers, which could derive from economic pressures on the breweries combined with a lack of regulations, or a change in consumer preference. So–called Pilsner beers with extremely low BU values are judged as a being misleading to the consumer, which is an offence against European food law. Copyright © 2015 The Institute of Brewing & Distilling     

The Interplay between HGF/c-met Axis and Nox4 in BRAF Mutated Melanoma

Background: Melanoma is the leading cause of death due to cutaneous malignancy and its incidence is on the rise. Several signaling pathways, including receptor tyrosine kinases, have a role in the development and progression of melanocytic lesions and malignant melanoma. Among those, the hepatocyte growth factor (HGF)/c-met axis is emerging as a critical player because it can play a role in drug resistance. Indeed, 50% of melanoma patients present BRAF mutations, however, all responders develop resistance to the inhibitors typically within one year of treatment. Interestingly, BRAF inhibitors induce reactive oxygen species (ROS) in melanoma cells, therefore, the aim of this study was to investigate a possible interplay between HGF/c-met and ROS sources, such as NADPH oxidases (Nox). Methods: The expression of c-met and Nox were quantified in 60 patients with primary cutaneous melanoma. In vitro experiments on melanoma primary cells and the cell line were performed to dissect the underpinned molecular mechanism. Results: The outcome of interest was the correlation between the high positivity for both Nox4 and c-met and metastasis occurring at least 1 year later than melanoma diagnosis in BRAF mutated patients, in contrast to nonmutated. In vitro experiments demonstrated that the axis HGF/c-met/Nox4/ROS triggers the epithelial-mesenchymal transition. Conclusions: The observed correlation suggests an interplay between c-met and Nox4 in promoting the onset of metastasis. This study suggests that Nox4 inhibitors could be associated to the current therapy used to treat melanoma patients with BRAF mutations.     

Evolution on neutral networks accelerates the ticking rate of the molecular clock

Large sets of genotypes give rise to the same phenotype, because phenotypic expression is highly redundant. Accordingly, a population can accept mutations without altering its phenotype, as long as the genotype mutates into another one on the same set. By linking every pair of genotypes that are mutually accessible through mutation, genotypes organize themselves into neutral networks (NNs). These networks are known to be heterogeneous and assortative, and these properties affect the evolutionary dynamics of the population. By studying the dynamics of populations on NNs with arbitrary topology, we analyse the effect of assortativity, of NN (phenotype) fitness and of network size. We find that the probability that the population leaves the network is smaller the longer the time spent on it. This progressive ‘phenotypic entrapment’ entails a systematic increase in the overdispersion of the process with time and an acceleration in the fixation rate of neutral mutations. We also quantify the variation of these effects with the size of the phenotype and with its fitness relative to that of neighbouring alternatives.     

Generation of Rho Zero Cells: Visualization and Quantification of the mtDNA Depletion Process

Human mitochondrial DNA (mtDNA) is located in discrete DNA-protein complexes, so called nucleoids. These structures can be easily visualized in living cells by utilizing the fluorescent stain PicoGreen^®. In contrary, cells devoid of endogenous mitochondrial genomes (ρ⁰ cells) display no mitochondrial staining in the cytoplasm. A modified restriction enzyme can be targeted to mitochondria to cleave the mtDNA molecules in more than two fragments, thereby activating endogenous nucleases. By applying this novel enzymatic approach to generate mtDNA-depleted cells the destruction of mitochondrial nucleoids in cultured cells could be detected in a time course. It is clear from these experiments that mtDNA-depleted cells can be seen as early as 48 h post-transfection using the depletion system. To prove that mtDNA is degraded during this process, mtDNA of transfected cells was quantified by real-time PCR. A significant decline could be observed 24 h post-transfection. Combination of both results showed that mtDNA of transfected cells is completely degraded and, therefore, ρ⁰ cells were generated within 48 h. Thus, the application of a mitochondrially-targeted restriction endonuclease proves to be a first and fast, but essential step towards a therapy for mtDNA disorders.